What is the importance of EM measurements in astrophysics?

[binbagsss]

I was asked this in a PhD interview and hit a blank, it seemed to open...

 

[phyzguy]

Um... virtually everything we know about astrophysics has come from measuring electromagnetic waves. Gravitational waves and neutrinos are the only exceptions I can think of and the number of those observations is miniscule compared to the number of EM wave observations.

 

[davenn]

I was asked this in a PhD interview and hit a blank, it seemed to open ...

What is the importance of EM measurements in astrophysics ? ...

Um... virtually everything we know about astrophysics has come from measuring electromagnetic waves. Gravitational waves and neutrinos are the only exceptions I can think of and the number of those observations is miniscule compared to the number of EM wave observations.

agreed with phyzguy, we use various forms of EM for almost all studies of the universe...
from low frequency radio waves to EHF radio ( microwaves) to infra red, visible light, ultraviolet, to x-rays and gamma rays
They are all EM in nature (all types of EM)

should have been an easy answer for a PhD student Dave

 

[JMz]

agreed with phyzguy, we use various forms of EM for almost all studies of the universe...
from low frequency radio waves to EHF radio ( microwaves) to infra red, visible light, ultraviolet, to x-rays and gamma rays
They are all EM in nature (all types of EM)

should have been an easy answer for a PhD student Dave

Should have been an easy answer for a high-school student. ;-)
There is one other type of observation we can occasionally make: chemical, when we have access to the atoms themselves, as with sample-return missions and the Mars rover and other "lander" missions. But again, the number of those observations is minuscule compared to EM (and we might quibble that these are not precisely astrophysical, as the OP asked, but "astrochemical".)